| Parallel robot has several advantages, such as great rigidity, stable frame, good carrying capacity and high movement precision. Parallel robot is easy to get the inverse solution, and is propitious to calculate online. So since the appearance of parallel robot, it has remedied the disadvantages of series robot and has extended the application areas of robot. This thesis has deeply researched the motion control of a 6-PRRS parallel robot.First, the kinematics model of the 6-PRRS parallel robot is established, and the inverse positional solutions are set to select easily. The Jacobian matrix of the 6-PRRS parallel robot has been computed by two methods. One is differential coefficient based on symbol operation, the other is vector construction. For the preparation of the real-time control of the 6-PRRS parallel robot, track planning is researched, including trapezoid planning and S curve planning. The harmony motion of six-axis is analyzed to get the movements of the slides.The dynamic model of the 6-PRRS parallel robot is developed for the dynamic control. First, the Jacobian matrix of the system is derived from a kinematics analysis. Then the dynamic equations for each part are deduced using the Newton-Euler method. At last the driving forces of the active joints are calculated, by using the principle of D'A lembert.Two kinds of controllers in linkspace are developed to accomplish the tracking control of the 6-PRRS parallel robot. The former is a robust auto-disturbance rejection controller (ADRC), which contains nonlinear tracking differentiator (TD), extended-states observer (ESO), nonlinear proportional derivative (N-PD) and compensation of unknown disturbance. The latter is using CMAC & PD controller and CONN & PD controller. The NN controllers are used to the forward control, and the PD controller is used to the feedback control.At last, the experiment system is established. The experiment successfully accomplishes the movement of the 6-PRRS parallel robot. |
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